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Laptop audio whine while charging

Discussion in 'General Hardware' started by Soylent Joe, Oct 3, 2011.

  1. Soylent Joe

    Soylent Joe

    May 27, 2009
    3,404 (1.10/day)
    Thanks Received:
    Brunswick, GA
    My dad has an Asus G73Jh that we got off craigslist a few weeks back. The GPU is faulty and when it's under load the system shuts off, but that's a separate problem. We hooked it up to the TV to watch a movie with the video going through VGA and the audio going to the AV receiver via 3.5mm to RCA. While charging a quite loud squealing/whining sound can be heard, and there is some faint static horizontal lines in the middle of the picture. When you unplug the charger both effects vanish. I also noticed on a recent road trip that something similar happens with my Acer netbook. While plugged into the power inverter, a squealing could be heard through the headphones.

    What could be causing this? Possibly sound drivers or "dirty" power coming from the source or chargers?
  2. robal


    Aug 5, 2008
    497 (0.15/day)
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    Hampshire, UK

    Modern chargers are all "switched-mode" type. If they're low quality (or old), they can geterate quite a lot of noise on their output, causing interference and such noise. ("dirty power")

    Car 12V -> mains AC inverter is even more noisy, and that's typical.

    While I cannot guarantee it, there's very good chance that the problem will go away if you get another charger (same specs!).

    Does your laptop use 12V or 19V charger ?
    If you use 12V, you can easily bypass noise inverter in car by using direct cable.
    Soylent Joe says thanks.

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